Armature bounce in solenoid actuated valves has and is a concern as the time of operation of the valve becomes faster and faster. In many instances, the solution has been to proving some form of dampening means when the armature is released from the actuated solenoid and the armature "slams" into a stop such as a valve seat.
U.S. Pat. No. 5,033,716, entitled "Electromagnetic Fuel Injector" by Mesenich teaches the use of hydraulic damping gaps on the armature and stator to reduce the bounce of the armature when it strikes the stator by allowing the fluid to be squeezed out from between the surfaces instead of forming a solid fluid link.
U.S. Pat. No. 4,978,072, entitled "Solenoid Actuated Valve Assembly" by Weinand, teaches the use of a resilient pad on the face of the stator to absorb the impact of the armature against the stator upon energization to reduce armature bounce. Upon de-energization, the armature and valve stem separate when the valve is closed and the valve-closing kinetic energy of the armature is dissipated without affecting closing.
U.S. Pat. No. 4,957,275, entitled "Control Valve" by Homes makes use of the principle of fluid dampening on the de-energization of the solenoid and the return of the armature to its normal position.
U.S. Pat. No. 4,878,650 entitled "Armature with Shear Stress Damper" by Daly makes use of viscous shearing of a mass on the armature to dampening the movement of the armature on the de-energization of the solenoid and the return of the armature to its normal position.